Carburetor



A. L. KIMBALL CARBURETOR Feb.- 17, 1931.

Original Filed Sept. 24, 1924 ATTORNEY.

, ANDREW I; IIIIIBALI., or DETROIT,

y yet smoot ly. It is possible toaccomplsh gine will not run when cold,

Reissue-d Feb. I7, 193i Re. was

.UNITED s'm'ras PATENT iol-"FICE MICHIGAN, AssIGNoR To THE WHEELER-scimmia cAmaUnETon co., or INDIANAroLIs, INDIANA,'A eoRroRATIoN or INDIANA eAIu'sImEToB.

reissue led Novemberv 5,

It is the primary object of my invention to make an automotive engine less liabl o stall when cold. A second object is to make 1t less likelythat an operator will-leave the mixture-enriching device of a carburetor set in the mixture-enriching position after the engine has reached its normal runnin temperature. A third object is to make t e engine easierl to start when4 cold.- f

It is customary to ad] ust the carburetor of an automotive engine so that when the latter is runnin idleV it will run quite slowly and this after the engine is thoroughly warmed up; but with this carburetor setting the enespecially at the low speeds. It is therefore customary to provide mixture-enriching devices toI facilitate both the starting of the engine and the running thereof during the warming-up period. Even with lsuch a mixture-enriching device, considerably more throttle is necessary to in-` sure continued running while the engine is cold than when it is hot. Inrother words, the engine is liable to stall when cold. at the low speeds-that are'found entirely satisfactory .when the engine is hot. Moreover, when a mixture-enriching device is set to its mixture- Y enriching position for starting 'a cold engine,

the operatorvery frequently Aforgets to return it to its normal position when the engine is warmed up.

Many types of carburetors make it easiest to start the engine when thel throttle is at or near some certain position, especially when the engine is cold. In certain cases,it is particularly hard to start with the throttle too wide open; while starting with it too nearly closed will frequently result in stalling. Inexpert operators often experience troublein starting due to vtheir inability to set the throttle in the best position, in addition to being annoyed by frequent stalling due to too low an engine speed when idling cold.

' By my Invention, I provide in connection with the mixture-adjusting device adevice which, when the'mixtu e-'adjusting device is set for starting cold, lautomatically sets the throttle in a position for easy Starti ng, and at the same time in a position which insures serial No. 73ans, mea september 24, l1924,. Appncauonror 1930. Serial No. 493,593, 1 f

a sufficient engine. speed to even when the engine is cold; and which upon thereturn of the mixture-adjusting device to its normal position allows the throttle likewise to return to its normal` idling position.

If the operator neglects to return .the mixture-adjusting device to its normal position prevent stalling i l after the engline 1s warmed up, he is soon reminded of t down his engine to its usual low vidling speed.

The accompanying drawing illustrates an apparatus embodying my invention asapplied to one particular carburetor: Figure 1 is a vertical section through a carburetor of the preferredrt pe, to which I have shown my invention app larged fragmentary elevation, showing interconnection mixture-controlling mem er. f

The careburetor has a mainbody 10, the

the

at fact by his ina-bility to slow v ied.;l and Figure 2 is an enbetween the throttle and the D outlet from which tothe engine is controlled by a throttle'll on a throttle-shaft '12. The throttle shaft 12 maybe operated in any usual way, and only'a part of the operating arm 13 of the throttle-shaft 12 is illustrated in Figure 2, because such normal operating-mechanism for the throttle-shaft constitutes my present invention.

Within the main body 10 of the carburetor, the .explosive mixture is produced by mixing the fuel and air, in any usual or convenient manner. The proportion of fuel and air in the mixture may be varied, as to enrich the mixtureffor starting, by manipulation of a shaft 15, which may be turned in any suitable way. As shown, the shaft 15 is provided with an operating arm 16, which may be operated by a Bowden wire 17, leading to any convenient control-point, such as the Idash-of an automobile. For my broad invention, it is immaterial how the shaft 15 controls the' proportion of fuel and air in as itis involved in certain no part of more s cie cornbinations which lI claim,'one mechanismby which such shaft controls the mixture proportions will be described later;

the mixture; but

invention contemplates an in'terconnection between 'the shaft 15 and the shaft 12,50 that when the shaft 15 is turned clockwise (Figures l and .2) to produce a richer mixture,

` 19, however,

as for starting or idling cold, the throttleshaft 12 will also be moved, to vproduce an opening of the throttle 11 to some extent. For this purpose, the shaft 12 is shown as having fixed thereto an arm 18, shown as havingv an adjustable abutment-screw' 19 in its end, and this abutment-screw 19 bears against a cam 2O fixed on the shaft 15. When the shaft 15 is rocked in a clockwiseI :direction, to enrich the mixture, the cam 2O acts on the screw 19 and arm 18 to rock the throttle-shaft 12 in a clockwise direction from the closed position in whichi such throttle-shaft .12 is shown. Such interconnection between the shafts 12 and 15 does not interfere with the wider opening of the throttle 11 than that produced by the interi action of the cam 20 and screw 19 y and if the throttle is open more than the opening such cam would cause, no movement of the throttle 11 is obtained by the movement of the shaft 15. The interaction of the cam 20 and screw makes it impossible for the throttle 11 to be completely'closed when the shaft 15 has been rocked in a clockwise direction;`

. so that this interconnection insures that the throttlell will be open at least to a definiteldy determined position when the mixture is a jstedy fory starting and idling with the engine farther, to any limits provided for normal cold. This not only facilitates starting, by producing la suicient opening of the throttle, but also prevents the operator from throttling down to those low speeds at which the engine' when cold would be liable to stall.

Of course, when the engine has warmed up, the Bowden wire 17 should be operated to return the shaft 15 toits normal position; after which the throttle 11 may be closed running. If this is not closed,` the operator is soon reminded of that fact by his inability to throttle down to low speeds.

While my invention is applicable to any type of mixture-adjusting means, operated by the movement of parts such as the shaft 15.,

I have show it in connection with a specific type of mixture-adjustment; as with that type of mixture-adjustment I have obtained .verybeneficial results. This particular mix-` ture-adjustment when used with my invention involves certain sub-combinations, which will be particularlypointed out in some of the more specific claims; but it is not essential to the broad combination.

In this particular mixture-adjustment, there is a fuel-control needle 25, suitably hung from the right-hand end of a connecting. le-l ver 26, to theKleft-hand end of which connecting lever is connected a secondary-air valve 27. The lever 26-is fulcrumed intermediately on a pivot in 28,car1`\'i`ed by the outer end of xed on the shaft 15. The mounting of the lever.26,'ho.wever, isnotdirectly on the pivot-pin 28, for the lever 26 has slidably mounted.thieleonl a sleeve 3 0, to which the mixing chamber having a .air admission opening,

pivotal-connection .of the arm 29 by the pivot pin 28 is made. By the turning of the shaft 15 in a clockwise direction, as to enrich the mixture forl starting and idling of a cold engine, the pivot pin 28 is swung to the left and upward.` The upward component of movement produces a lifting of the needley valve 25, without any corresponding movement of the secondary-air valve 27 and thus produces an enriching of the mixture directly. The leftward component of movement of the pivot-pin 28 varies lengths of the parts of the lever 26, and thus increases the rate of opening of the needle valve 25 for a given rate of opening of the secondary-air valve 27. Thus when they shaft 15 is set at its counter-clockwise limit of movement, for normal operation after the engine the relative lever-armv soI for a given opening of the secondary-air valve 27 is at a minimum, resulting in high economy and eliiciency of operation; whereas when the shaft 25 is movedin a clockwise direction from the position shown, whether to thewlimit of movement of such clockwise direct on or not, the needle 25 is lifted positively by such movement, to produce a richer mixture, and also is arranged to have a proportionately greater opening movement for any given opening movement of thev secondary-air valve 2 l Iclaim as my invention:

1. In a carburetor, the combination of a fuel nozzle and an air-admission opening, a fuel-adjusting needle, an air controllingvalve, a lever connecting said needle and valve, means for shifting the fulcrum of said lever, a throttle, and means operated bysaidl fulcrum-shifting means for variably limiting the closing of' saidl throttle. v 2. In a carburetor, the combination of a. mixing chamber having a fuel nozzle and an i a fuel adjusting needle, an air-controlling valve, a lever connecting said needle and valve, means for varying the relative lengths of the arms of said levera throttle,

varying of said relative lever-arm lengths for varably limiting the closing o f said.v

throttle. v

3. In a carburetor, the combination of a mixing chamber having a fuel nozzle and an air-admission opening, a fuel-adjusting needle, an air-controlling valve, a; lever connecting said needle and valve, means for varying the fuel opening produced at said needle and means operated by the y for a given opening at' said air-controlling v valve, and means operated by said needlecontrolling means for .variably limiting the closing of said throttle.

4. In a carburetor the combination of a manually controllable fuel mixture enrichening device, a throttle movable separately therefromr and controlling the .flow of air throu h the carburetor, a cam associated with said evice, and a lever connected with the throttle and adapted to en age said cam, said cam being so formed as to 'mit the closing of 5 the throttle as the nxtureenrichening device approaches its reclining position for starting purposes.

5. In a carburetor including a casing, a throttle associated ltherewith operable from ,o a remote point, a shaft carried by said casing for transmitting movement to said throttle,

a mixture enrichening device and a second shaft carried by said casing for operating said device, mechanism mounted in close proxim- 15 ity to said casing in association with both of said shafts adapted to actuate said throttle shaft to slightly open said throttle whenever said second shaft is actuated in a direction for Y engine .starting purposes, s aid mechanism be- 0 ing mounted on said second shaft for actin on said throttle shaft and to remain una fected by remote control of said throttle.

In testimony whereof I have hereunto subscribed my name at Detroit, Wayne County,

25 Michigan.

' ANDREW L. KIMBALL. 

